The impact of oceanic microbial communities on marine biogeochemistry now and in the future

海洋微生物群落对现在和未来海洋生物地球化学的影响

• 批准号: RGPIN-2021-04060
• 负责人: LaRoche, Julie
• 金额: $ 2.4万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=745775
• 关键词: impact; oceanic; microbial; communities; marine

The overarching goal of the proposed research program is aimed at understanding the response of the microbial community (collectively phytoplankton and other microbes) to increasing seawater temperature and decreasing nutrient inventory and how this will affect primary productivity in the Northwest Atlantic (NWA) and other under-sampled regions of the world's ocean. A multi-pronged approach engages established microbial observatories in the NWA, including weekly to annual sampling of in-shore stations (Bedford Basin), spring and fall missions on the Scotian Shelf (in collaboration with DFO), and yearly sampling in the Labrador Sea. The research builds on established international collaborations (GEOMAR, WHOI) and develops new ones (AWI, IUEM, CIIMAR), thereby linking to international time-series and ensuring interoperability of the observations. Extending the research on microbial community structure and function within the context of the NWA, the PI will transfer her expertise to the study of microbial communities associated with the aquaculture industry. The proposed research builds on previous work on diazotrophs and nitrogen fixation as well as their associated microbial communities. In recent years, it has become clear that non-photosynthetic microbes make up the bulk of the diazotroph diversity. It is important to assess the contribution and function of the non-photosynthetic diazotrophs in the context of their global cell metabolism and within their characteristic microbial community, in addition to their ability to fix nitrogen. In a recent breakthrough in the PI's laboratory, the isolation of a widely distributed heterotrophic diazotroph has led to characterization of the production of polyhydroxybutyrate (PHB) linked to the diazotrophic lifestyle, a compound used in the synthesis of biodegradable plastic. Further studies will use transcriptomic, proteomic, and metabolomic approaches to elucidate the metabolism of this microorganism. The proposed research will rely on established time-series platforms to carry out the following objectives: i) With the microbial observatory in the NWA, establish the current baseline and associated variability in the microbial community to characterize strategic locations in the NWA (Coastal embayment, Scotian Shelf, and Labrador Sea). This will serve to explore how microbial community composition and metabolic function respond to changes in environmental conditions. ii) Perform manipulative experiments on natural microbial communities and new microbial isolates, including N2-fixing microbes (diazotrophs), from the Scotian Shelf and the NWA. iii) Transfer the developed approaches and the knowledge gained from objectives (i) and (ii) to specific aquaculture settings in order to compare and contrast microbial communities of salmon aquaculture farms and those of the surrounding coastal areas including the Scotian Shelf.

拟议研究计划的总体目标是了解微生物群落（浮游植物和其他微生物）对海水温度升高和养分库存减少的反应，以及这将如何影响西北大西洋（NWA）和其他地区的初级生产力。 - 世界海洋区域的采样。多管齐下的方法涉及 NWA 已建立的微生物观测站，包括每周到每年对近岸站（贝德福德盆地）进行采样、在斯科舍大陆架进行春季和秋季任务（与 DFO 合作）以及每年在拉布拉多海进行采样。该研究建立在已建立的国际合作（GEOMAR、WHOI）的基础上，并开发新的合作（AWI、IUEM、CIIMAR），从而与国际时间序列联系起来并确保观测的互操作性。在 NWA 的背景下扩展微生物群落结构和功能的研究，首席研究员将把她的专业知识转移到与水产养殖业相关的微生物群落的研究中。拟议的研究建立在先前关于固氮菌和固氮及其相关微生物群落的工作的基础上。近年来，人们已经清楚非光合微生物构成了固氮微生物多样性的大部分。除了固氮能力之外，评估非光合固氮生物在其整体细胞代谢及其特征微生物群落中的贡献和功能也很重要。 PI 实验室最近取得了突破，分离了广泛分布的异养固氮菌，从而对与固氮生活方式相关的聚羟基丁酸酯 (PHB) 的生产进行了表征，PHB 是一种用于合成可生物降解塑料的化合物。进一步的研究将使用转录组学、蛋白质组学和代谢组学方法来阐明这种微生物的代谢。拟议的研究将依靠已建立的时间序列平台来实现以下目标：i）通过 NWA 的微生物观测站，建立微生物群落的当前基线和相关变异性，以描述 NWA 的战略位置（沿海海湾、斯科舍大陆架和拉布拉多海）。这将有助于探索微生物群落组成和代谢功能如何响应环境条件的变化。 ii) 对来自斯科舍大陆架和 NWA 的自然微生物群落和新的微生物分离株进行操作实验，包括固氮微生物（固氮微生物）。 iii) 将开发的方法和从目标（i）和（ii）中获得的知识转移到特定的水产养殖环境中，以便比较和对比鲑鱼水产养殖场和包括斯科舍大陆架在内的周围沿海地区的微生物群落。